KR100355503B1 - Radio communication terminal and method - Google Patents

Abstract

According to the present invention, the common first search code is made common in FDD / TDD. By measuring the reception level of both the first search code of the FDD and the first search code of the TDD, the mobile station determines which way to connect or switch. In a dedicated system, a different first search code is used for each system. Therefore, in the terminal device that can cover the dedicated mode, the first search code is known. In the dedicated / public period, the mobile station determines which one to connect or switch to by measuring the reception levels of both the dedicated first search code and the shared first search code.

Description

Communication terminal device, base station device and wireless communication method {RADIO COMMUNICATION TERMINAL AND METHOD}

The present invention relates to a communication terminal device and a wireless communication method used in a digital wireless communication system.

Code Division Multiple Access (CDMA) has been developed as a multiple access method used in the next generation mobile communication method. In this multiple access system, a duplex system such as a frequency division duplex (FDD) system or a time division duplex (TDD) system is adopted. FDD is a method of performing communication using different bands for transmission and reception, and TDD is a transmission / reception co-band method, also called a ping pong method, and is a method of communicating by time-dividing the same radio frequency by transmission / reception.

Recently, in the CDMA, a system using the FDD scheme and the TDD scheme has been researched and developed, and standardization has been conducted. For this reason, the development of a common apparatus (dual mode terminal apparatus) which can use both an FDD system and a TDD system on the communication terminal side is expected in the future. The common equipment will have the ability to connect individually for each type.

On the other hand, in a wireless communication system, a so-called public system, in which a specific operator company provides a service to an unspecified user, and a private or corporate dedicated service for providing a service to a specific user, for example, an employee in an enterprise. There is a private system.

However, in common equipment that can use the CDD FDD and TDD schemes, each of them has a function that can be individually connected to each scheme, and has a function of selecting and switching a system according to a communication situation or a radio wave environment. Not. Moreover, even in a shared system and a dedicated system, it is not performed to select and switch a system according to a communication situation or a radio wave environment.

As described above, although various different systems, for example, an FDD system and a TDD system, a common system, and a dedicated system are used, the selection and switching of systems between heterogeneous systems according to communication conditions and radio wave environments are not performed. This is the current state, and no specific measures have been taken.

An object of the present invention is to provide a communication terminal apparatus and a wireless communication method capable of selecting and switching a system according to a communication situation or a radio wave environment between heterogeneous systems.

The present inventor focuses on mask symbols used in initial synchronization establishment work when the mobile station turns on the power, cell search such as cell handover accompanying movement, and when this mask symbol structure is common, The present invention has been found that the system can be selected and switched in accordance with the communication situation and the radio wave environment between the systems.

In the FDD method, a mask symbol structure as disclosed in Higuchi, Sawabashi, and Adachi, "a fast cell search method using a long code mask in asynchronous cellular between DS-CDMA base stations" (IEICE RCS96-122,1997-01). Has been reviewed and K.Miya, O.Kato, etc. are also used in the TDD system. The introduction of the same mask symbol structure is disclosed as disclosed in "Wideband CDMA System in TDD-mode Operation for IMT-2000" (IEICE Trans. Commun., Vol. E81-B, No. 7, July 1998). .

That is, the main point of the present invention is that in different systems (shared / dedicated FDD and shared / dedicated TDD) having symbols (mask symbols) spread only by the short code in the downlink control channel (CCH), By using this mask symbol, a high-speed cell search is performed, and the selection and switching (handover) of a system to be connected is realized at the time of power-on and at the time of subsequent call or call waiting.

The above and other objects, features, aspects, advantages, and the like of the present invention will become more apparent from the following detailed embodiments described with reference to the accompanying drawings.

1 (a) is a diagram showing a slot configuration in a CDMA / FDD scheme;

1 (b) shows a slot configuration in a CDMA / TDD scheme;

2 (a) is a diagram showing a frame structure in a CDMA / FDD scheme;

2 (b) is a diagram showing a frame structure in a CDMA / TDD (common) system;

2 (c) is a diagram showing a frame structure in the CDMA / TDD (dedicated) method;

3 is a diagram showing a frequency band in the CDMA / FDD and TDD schemes;

4 is a block diagram showing a configuration of a communication terminal device according to Embodiment 1 of the present invention;

Fig. 5 is a block diagram showing the configuration of a base station apparatus which performs wireless communication with a communication terminal apparatus according to the first embodiment of the present invention;

6 is a block diagram showing a detailed configuration of a spreading modulation circuit in the base station apparatus shown in FIG. 5;

7 (a) to 7 (c) are diagrams illustrating a relationship between a system, a base station apparatus, and a communication terminal apparatus in a wireless communication system using the communication terminal apparatus of the present invention;

Fig. 8 is a diagram for explaining the timing of system connection and handover in the communication terminal device of the present invention.

Explanation of symbols for the main parts of the drawings

401: antenna 402: wireless receiving circuit

403: matched filter 404: search circuit

405: sampling circuit 406: demodulation circuit

407: memory circuit 408: comparison selection circuit

409: connection processing control circuit 410: control circuit

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to an accompanying drawing.

(Example 1)

The communication terminal device according to the present embodiment realizes the selection and switching (handover) of a system between different systems having a common structure of a mask symbol used in cell search.

In this embodiment, system selection and switching between heterogeneous systems of the CDD FDD scheme and the TDD scheme will be described.

The symbol structure in one slot of the control channel in the downlink of the CDMA FDD scheme is as shown in Fig. 1A. That is, the first search code (FSC) 103 is inserted in front of the data (101) in one slot, and the pilot symbol (PL) 102 which is a known signal behind the data (101). ) Is inserted. In the CDMA / FDD scheme, communication is performed in the slot of the above configuration in a frame configuration as shown in Fig. 2A (here, 16 slots in a unit frame (for example, one frame)).

On the other hand, the symbol structure in one slot of the control channel in the TDD system of CDMA is as shown in Fig. 1B. That is, the pilot symbol (PL) 102 and the first search code (FSC) 103, which are known signals, are inserted between the data 101 in one slot, and the end of the data 101 Guard section G (104) is provided in i). In the CDMA / TDD scheme, the slot of the above configuration is shown in FIG. 2 (b). The slot configuration of the first and ninth slots is the downlink control channel, followed by the uplink (UL) communication channel. It is assumed that the communication channel of 3 slots and downlink DL is 4 slots continuous. In addition, unlike the configuration of FIG. 2 (b), the communication channel has no mask symbol.

Although the frequency bands used are different from each other as shown in Fig. 3 (FDD is f1 to f2 and TDD is f3 to f4 in Fig. 3), the FDD method and the TDD method are shown in Figs. 1A and 2B. As shown in the figure, a symbol structure having a mask symbol (first search code) is common. By using this common mask symbol structure, system selection and switching between the FDD system and the TDD system are performed.

4 is a block diagram showing the configuration of a communication terminal apparatus according to Embodiment 1 of the present invention. In this radio communication apparatus, the received signal is received by the radio receiving circuit 402 via the antenna 401. In the radio reception circuit 402, predetermined radio reception processing is performed on the reception signal. The received signal is despread by the matched filter 403 and sampled by the sample circuit 405 and demodulated by the demodulation circuit 406 for the bus at the timing detected by the search circuit 404. It becomes data.

In addition, the search circuit 404 confirms the timing of the first search code and checks the timing of the first search code in the cell search such as initial synchronization establishment work when the power is turned on or cell handover associated with movement. Detects the reception level of the search code. The reception level is sent to the memory circuit 407 and stored. The reception level stored in this memory circuit 407 is sent to the comparison selection circuit 408, and the reception level is compared.

In the comparison selection circuit 408, a threshold value determination is performed on the reception level of the first search code, and the connection selection control signal (not shown) is switched to the system of the first search code higher than the predetermined threshold value. 409). In accordance with this connection target selection signal, the connection processing control circuit 409 controls the connection processing to the system to be connected. In addition, the control circuit 410 controls the radio receiver circuit 402, the matched filter 403, the search circuit and the memory circuit 407 in response to the case where a signal of each system is received.

The demodulated signal in the demodulation circuit 406 is also sent to the comparison selection circuit 408 and used to calculate the parameters for system selection.

Fig. 5 is a block diagram showing the configuration of a base station apparatus which performs wireless communication with a communication terminal apparatus according to the first embodiment of the present invention. In this base station apparatus, the control channel signal, which is the transmission data, is subjected to primary modulation processing such as orthogonal modulation in the data modulation circuit 501, and is sent to the diffusion modulation circuit 502 for diffusion processing with a predetermined spread code. . The modulated transmission signal is sent to the radio transmission circuit 503 to perform a predetermined radio transmission process, and then transmitted via the antenna 504.

6 is a block diagram showing the detailed configuration of the spreading modulation circuit 502 in the base station apparatus. In this apparatus, after the data is modulated by the data modulation circuit 501, the short code SC0 and the long code LCj multiplied by the multiplier 602 in advance are data modulated by the multiplier 601. Multiply by

The search code is multiplexed at the mask symbol position in this signal. The multiplexing of this search code is executed by the mask control signal. That is, this search code is a mask control by which the first search code (FSC) used for chip synchronization and reception timing and the second search code (SSC) for group identification are multiplexed by the multiplexer 604. The signal is multiplexed by switching the switch 603 according to the signal.

Next, a connection selection and switching operation between different systems in a wireless communication system having a communication terminal device having the above configuration will be described.

A description will be given when the communication terminal device A shown in FIG. 7A turns on the power supply. Here, the system 1 is the CDMA / TDD system, and the system 2 is the CDMA / FDD system. In addition, the frame structure in the FDD scheme is as shown in FIG. 2 (a), and the frame structure in the TDD scheme is as shown in FIG. 2 (b), all of which include the first search code. Has the structure of. In addition, the base stations 701 and 702 are equipped with the radio communication apparatus of the structure shown in FIG. 5 and FIG. 6, and the communication terminal apparatus A, B is equipped with the communication terminal apparatus of the structure shown in FIG.

The base station 701 transmits the signal of the TDD method shown in FIG. 2 (b), and the base station 702 transmits the signal of the FDD method shown in FIG. 2 (a). In the base stations 701 and 702, the first search code FSC and the second search code SSC are time-multiplexed to the part which masks the control channel signal which is transmission data, respectively. The first search code FSC and the second search code SSC are appropriately switched by the switch 603 according to the mask control signal of the pulse waveform shown in FIG. 6 and multiplexed with the control channel signal.

In addition, the short code SC0 multiplied by the multiplier 602 and the long code LCj are multiplied by the multiplier 601 to the control channel signal. The signal thus processed is transmitted through the antenna 504 after the predetermined radio transmission processing is performed in the radio transmission circuit 503.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702. Since the signals from the base stations 701 and 702 are signals having a common mask symbol structure, the same processing can be performed in the cell search even when the signals are from different systems.

The communication terminal device A first executes a process on a signal from the system 1 from the base station 701. That is, after switching to the frequency of the TDD band, the matching filter 402 and the search circuit 404 perform timing detection by the first search code. Specifically, a reception value is detected by performing a despreading process on a symbol (mask symbol) spread only by the first search code common to each system to obtain a correlation value, and detecting the position of the highest correlation value. The quality of the first search code at the detected timing, for example, the reception level, is stored in the memory circuit 407.

Subsequently, processing is performed on the signal in the system 2 from the base station 702. That is, in the same manner as described above, after switching to the reception frequency of the FDD band, the matching filter 402 and the search circuit 404 execute timing detection by the first search code, and then perform the first search at the detected timing. The reception level of the code is stored in the memory circuit 407. In addition, switching between the signal processing of the system 1 from the base station 701 and the signal processing of the system 2 from the base station 702 is executed by the control circuit 410.

In addition, although the signal processing in the system 1 from the base station 701 is first performed here, the signal processing in the system from the base station 702 may be performed first, and if there is no problem in hardware, The signals from both base stations may be processed simultaneously.

The signal reception level of each system stored in the memory circuit 407 is compared by the comparison selection circuit 408. The comparison selection circuit 408 selects the system having the higher reception signal level and sends a connection target selection signal to the connection processing control circuit 409 indicating that the system is connected to the system having the highest signal level.

For example, since the communication terminal device A exists in the system 1 in the case shown in Fig. 7A, the signal from the base station 701 (system 1) (solid line) under a normal radio wave environment. ) Is increased, and the level of the signal (dashed line) from the base station 702 (system 2) is lowered. Therefore, in the comparison selection circuit 408, the system 1 with a high signal level is selected as the connection target system, and the connection processing from the connection processing control circuit 409 to the system 1 is executed.

The same process as described above is performed even when the communication terminal device B shown in Fig. 7A is turned on. That is, the communication terminal device B also receives a signal having a common mask symbol structure from each of the base stations 701 and 702. As in the case of the communication terminal apparatus A, processing is performed on the signals from the base station 701 and the base station 702, respectively, and the reception level of the first search code of each system is stored in the memory circuit 407. do. In the comparison selection circuit 408, the system having the higher reception signal level is selected, and the connection target selection signal indicating that the system is connected to the system having the highest signal level is sent to the connection processing control circuit 409.

For example, in the case shown in Fig. 7A, since the communication terminal device B exists in the system 2, the signal from the base station 702 (system 2) (solid line) under a normal radio wave environment. ), The level of the signal (dotted line) from the base station 701 (system 1) is lowered. Therefore, in the comparison selection circuit 408, the system 2 with a high signal level is selected as the connection target system, and the connection processing from the connection processing control circuit 409 to the system 2 is executed.

Next, the case where the communication terminal device A shown in FIG. 7 (b) or 7 (c) performs handover (HO) from the system 1 to the system 2 will be described.

The base station 701 transmits a signal of the TDD method shown in FIG. 2 (b), and the base station 702 transmits a signal of the FDD method shown in FIG. 2 (a). In the base stations 701 and 702, the first search code FSC and the second search code SSC are time-multiplexed to the part which masks the control channel signal which is transmission data, respectively. The first search code FSC and the second search code SSC are suitably switched by the switch 603 according to the mask control signal of the pulse waveform shown in FIG. 6, and multiplexed as a mask with respect to the control channel signal.

In addition, the short code SC0 multiplied by the multiplier 602 and the long code LCj are multiplied by the multiplier 601 to the control channel signal. The frame-configured signal is transmitted via the antenna 504 after the predetermined radio transmission processing is performed in the radio transmission circuit 503.

The communication terminal device A is performing communication with the base station 701 of the system 1 (X area in FIG. 8). When the communication terminal device A is close to the area of the system 2 and the first search code reception level of the downlink control channel between the base station 701 is low, that is, shown in FIG. As described above, when the reception level in the system 1 decreases to be lower than the threshold value 1 and the reception level in the system 2 becomes higher than the threshold value 2, the system 1 enters the handover state (Y area in FIG. 8). It also communicates with the base station 702 of the system 2. Specifically, a signal having a common mask symbol structure is also received from the base station 702, and the initial access process is executed for the base station 702. FIG. Since the signals from the base stations 701 and 702 are signals having a common mask symbol structure, the same processing can be performed in the cell search even if the signals are from other systems.

When the reception level in the system 2 exceeds the threshold 1 and the reception level in the system 1 is less than the threshold 2, the communication terminal device A disconnects from the system 1, It connects only to system 2 and communicates with base station 702 (Z area in FIG. 8). Also in this case, it becomes possible to connect to different systems.

As described above, in the present embodiment, by using signals having a common mask symbol structure in different systems, connection targets can be automatically detected between different systems (FDD / TDD).

(Example 2)

In the second embodiment, between the different systems, only the reception level in one system is first measured and the connection is judged by threshold determination, and the reception level of the other system is determined only when the reception level is below the threshold. The case of measuring and connecting is demonstrated.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702. First, the signal from the system 1 from the base station 701 is processed. That is, the matching filter 402 and the search circuit 404 perform timing detection by the first search code. Specifically, the reception value is detected by performing a despreading process on a symbol (mask symbol) spread only with the first search code common in each system to obtain a correlation value, and detecting the position of the highest correlation value.

Then, the threshold value is determined for the reception level of the first search code at the detected timing. When the detected reception level exceeds a predetermined threshold, the communication terminal device A sends a connection target selection signal indicating that it is connected to the system 1 to the connection processing control circuit 409 and performs connection processing to the system 1. Is executed.

On the other hand, when the reception level is equal to or less than a predetermined threshold, the communication terminal device A executes processing on a signal from the base station 702 having a common mask symbol structure. That is, in the same manner as above, the matching filter 402 and the search circuit 404 execute timing detection by the first search code, and the memory circuit 407 sets the reception level of the first search code at the detected timing. Store in In addition, switching between the signal processing of the system 1 from the base station 701 and the signal processing of the system 2 from the base station 702 is executed by the control circuit 410.

Then, threshold determination is performed in the same manner as described above with respect to the reception level of the first search code at the detected timing. When the detected reception level exceeds a predetermined threshold, the communication terminal device A sends a connection target selection signal indicating that it is connected to the system 2 to the connection processing control circuit 409 so that connection processing is performed to the system 2. Is executed.

As described above, since only the reception level in one system is measured first and the connection is judged by threshold determination, the reception level of the other system is measured and connected only when the reception level is less than or equal to the threshold value. The comparison process becomes unnecessary, which enables a quick connection process for the optimal system.

In addition, although the signal processing in the system 1 from the base station 701 is performed first here, the signal processing in the system from the base station 702 may be performed first.

(Example 3)

In the present embodiment, the case where the required transmission power, which considers not only the reception level of the first search code but also the radio wave loss and the interference amount, is used when determining the connection or switching of the communication terminal. These parameters execute not only the first search code but also the second search code to perform a series of initial synchronization processes to decode the data of a notification channel such as a perch channel, thereby receiving information (base station transmission level, The interference level at the base station). Accordingly, it is possible to select a system that can be connected at the weakest output or a system with low congestion.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702. Since the signals from the base stations 701 and 702 are signals having a common mask symbol structure, the same processing can be performed in the cell search even if the signals are from different systems.

First, similarly to the first embodiment, processing is performed on the signal in the system 1 from the base station 701 and processing is performed on the signal in the system 2 from the base station 702. Then, the reception level of the first search code at the detected timing is stored in the memory circuit 407, respectively.

Next, the long code candidate to be searched is defined using the second search code, and the long code unique to the cell is specified from the long code candidate. In this way, after performing a series of initial synchronization processes, the data of a notification channel such as a perch channel is decoded to reduce propagation loss or interference amount from information notified from the notification channel, for example, the base station transmission level and the interference level at the base station. It is possible to calculate the required transmission power in consideration of the result.

Specifically, the notification channel signal is despread by the matching filter 403 after being wirelessly received by the wireless receiving circuit 402 and simultaneously sampled 405 for the bus at the timing detected by the searching circuit 404. Is sampled at < RTI ID = 0.0 >, < / RTI > This control signal data is arithmeticly processed by an arithmetic unit (not shown), whereby the required transmission power in consideration of the propagation loss and the amount of interference is obtained. The obtained required transmission power is sent to the comparison selection circuit 408. This process is performed for the base stations 701 and 702, respectively.

In the comparison selection circuit 408, the level comparison is performed on the reception levels of the system 1 and the system 2 stored in the memory circuit 407, and the required transmission power of each of the base stations 701 and 702 is compared. The comparison is also selected. The comparison selecting circuit 408 then selects a preferred system for the connection object in consideration of the reception level and the required transmission power, informs the connection processing control circuit 409 of such contents, and performs the connection processing on the selected system.

As described above, in the present embodiment, when the connection or switching determination of the communication terminal device is used, not only the reception level of the first search code but also the required transmission power in consideration of the radio wave loss and the amount of interference are used. The connection target can be selected correctly. In addition, according to this, it is possible to select a system that can be connected at the weakest output and a system with low congestion.

In the present embodiment, the case where the required transmission power, which considers not only the reception level of the first search code but also the radio wave loss and the amount of interference (system congestion), is used when determining the connection or switching of the communication terminal device. In addition to these parameters, the present invention considers communication contents in the system, such as voice communication, low speed / high speed packet communication, data communication, and handover frequency such as moving speed of a communication terminal device. Therefore, the present invention can be applied even when the communication terminal device determines the connection target system.

In particular, when determining the connection target system of the communication terminal device, by considering the handover frequency and the contents of the service, it is possible to avoid connecting with a system in which the reception level is unexpectedly increased, which is optimal even when the communication terminal device is moving. The connection target can be selected.

(Example 4)

In the present embodiment, the communication terminal device requests a desired communication service for a system requested for connection, and reports information such as reception level information and congestion degree of another system measured by itself, and the base station reports from the communication terminal device. The case where the system status is determined based on the information of the user and the system to which the connection target system is introduced is explained.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702, and processes the signal in the system 1 from the base station 701 as in the first embodiment. Do it. Next, in the same manner as in the third embodiment, the long code candidate to be searched using the second search code is defined, and the long code unique to the cell is specified from the long code candidate. After performing a series of initial synchronization processes in this manner, data of the notification channel such as the perch channel is decoded to obtain information such as the congestion degree of the system 1 from the information informed from the notification channel. The same processing is also performed on the system 2 to obtain information such as the degree of congestion of the system 2.

The communication terminal device A notifies the base station 701 of the system 1 requesting a connection of information such as the degree of congestion of the system 1 and the system 2 obtained. The base station 701 determines the situation of the system 1 that is its own system based on the information such as the degree of congestion reported from the communication terminal device A. FIG. As the situation determination here, a threshold value determination for a parameter such as a congestion degree reported from the communication terminal device A can be used.

When it is determined that the accommodation is difficult in the system 1, another system capable of accommodating the communication terminal device is detected at this time. For example, the base station 702 of the system 2 reported from the communication terminal device A is contacted to check whether the communication terminal device A can be accommodated. As a result, when the communication terminal apparatus A can be accommodated in the system 2, the communication terminal apparatus A is notified (introduced) as the system 2 as a connection target.

Subsequently, the communication terminal device A executes a connection process for the system 2.

This connection process is the same in the case of the initial connection process or the handover process.

According to the present embodiment, since the base station judges the situation of its system based on the information from the communication terminal device and introduces the connection target system, the communication terminal device can quickly know the acceptable system at that time, and quickly You will be able to connect to that system.

In the present embodiment, the case where the base station introduces another system capable of accommodating the communication terminal apparatus to the communication terminal apparatus is described. However, in the present invention, a plurality of other base stations in which the base station can accommodate the communication terminal apparatus are described. The system may be introduced to a communication terminal device, and the communication terminal device may execute a process as described in Embodiments 1 to 3 for the plurality of systems to select a connection target system.

(Example 5)

In this embodiment, a case where different systems are a shared system and a dedicated system will be described. First, a description will be given when the communication terminal device A shown in Fig. 7A is turned on.

Here, the system 1 is a dedicated system of the CDMA / TDD system, and the system 2 is a shared system of the CDMA / TDD system. The frame structure in the common system is as shown in Fig. 2 (b), and the frame structure in the dedicated system is as in Fig. 2 (c), and all have a common structure including the first search code. have. In this case, it is assumed that the first search codes SC0 to SC3 of the shared system and the dedicated system are known.

In addition, the base stations 701 and 702 are provided with the radio communication apparatus of the structure shown in FIG. 5 and FIG. 6, and the communication terminal apparatus A, B is equipped with the radio communication apparatus of the structure shown in FIG.

The base station 701 transmits a signal of any of the systems 1-1 to 1-3 of the TDD signal shown in Fig. 2C, and the base station 702 shows the signal shown in Fig. 2B. The TDD signal is transmitted. In the base stations 701 and 702, the first search code FSC and the second search code SSC are time-multiplied to a portion for masking the control channel signal which is transmission data, respectively. The first search code FSC and the second search code SSC are appropriately switched by the switch 603 according to the mask control signal of the pulse waveform shown in FIG. 6, and multiplexed with respect to the control channel signal.

The short code SC0 multiplied by the multiplier 602 in advance and the long code LCj are multiplied by the multiplier 601 to the control channel signal. The frame-configured signal is transmitted in the radio transmission circuit 503 via the antenna 504 after the predetermined radio transmission processing.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702. The signals from the base stations 701 and 702 are signals having a common mask symbol structure, and since the first search code in each signal is known, even in the case of signals from different systems, the cell search is performed. Similar processing is possible.

In the communication terminal device A, detection is performed after timing detection by the first search code is performed on the signals of the systems 1 and 2 from both base stations 701 and 702 in the same manner as in the first embodiment. The quality of the first search code, for example, the reception level, at the established timing is stored in the memory circuit 407.

The reception level of each system signal stored in the memory circuit 407 is compared by the comparison selection circuit 408. The comparison selection circuit 408 selects a system having a higher reception level and sends a connection target selection signal to the connection processing control circuit 409 indicating that the system is to be connected to a system having a higher reception level. Perform.

In addition, similarly to the first embodiment, the same processing as described above is performed even when the communication terminal device B shown in Fig. 7A is turned on. Moreover, also when the communication terminal apparatus A handovers (HO) from system 1 (dedicated system) to system 2 (public system) as shown to FIG. 7 (b) or 7 (c). It can be carried out similarly to the first embodiment.

As described above, in the present embodiment, by using signals having a common mask symbol structure in different systems, the connection target can be automatically detected between different systems (dedicated system and shared system).

Further, the first search code in the dedicated system is the same as the first search code in the shared system, and the dedicated or shared is identified by the processing after the second search code, or that it is its own dedicated system. It is possible. However, as in this embodiment, even when the dedicated system coexists at the same frequency by setting the first search codes in the dedicated system differently (SC1 to SC3) for each system, the magnetic system identification by the communication terminal apparatus is performed. It is also possible to easily perform with only the first search code. Further, dozens or hundreds of first search codes of the dedicated system are prepared, and the base stations of each system autonomously set the first search code as the first search code of the own system, or the base station of each dedicated system is set to the first. The reception level of the retrieval code can be detected to easily find a first retrieval code not being used in the vicinity, and the first retrieval code can be set as the first retrieval code of the magnetic system.

(Example 6)

In this embodiment, between the different systems, only the reception level in the dedicated system is first measured to determine whether to connect by threshold determination, and the reception level of the shared system is measured only when the reception level is below the threshold. The case where the connection is performed will be described.

The communication terminal device A receives a signal having a common mask symbol structure from each of the base stations 701 and 702, but first, processes a signal in a dedicated system from the base station 701. In other words, the matching filter 402 and the search circuit 404 detect the timing by the first search code. Specifically, the reception timing detection is performed by performing a despreading process on a symbol (mask symbol) spread only by the first search code common to each system to obtain a correlation value, and detecting the position of the highest correlation value.

The threshold value is then determined for the reception level of the first search code at the detected timing. When the detected reception level exceeds a predetermined threshold, the communication terminal device A sends a connection target selection signal to the connection processing control circuit 409 informing that the connection to the dedicated system is performed.

On the other hand, when the reception level is equal to or less than a predetermined threshold, the communication terminal device A executes processing on a signal from the base station 702 having a common mask symbol structure. That is, similarly to the above, the matching filter 402 and the search circuit 404 execute timing detection by the first search code, and the memory circuit 407 sets the reception level of the first search code at the detected timing. Store in The control circuit 410 performs switching between the processing of the system 1 signal from the base station 701 and the processing of the system 2 signal from the base station 702.

The threshold value is then determined in the same manner as above for the reception level of the first search code at the detected timing. If the detected reception level exceeds a predetermined threshold, the communication terminal device A sends a connection target selection signal to the connection processing control circuit 409 informing that it is connected to the shared system, and the connection processing is performed for the shared system.

As described above, according to the present embodiment, first, only the reception level of one system is measured, and whether or not the connection is determined by the threshold value determination is determined, and only when the reception level is less than or equal to the threshold value, the reception level of the other system is measured. Since the system is selected and connected in accordance with the communication situation and the radio wave environment, the comparison process of the reception level is unnecessary, and the connection process can be executed quickly for the optimal system.

In addition, although the signal processing in the dedicated system from the base station 701 is first performed here, the signal processing in the shared system from the base station 702 may be performed first.

In the dedicated / public systems of the fifth and sixth embodiments described above, by making the configuration of the physical layer related to the initial synchronization after the second search code common or nearly identical to those in the dedicated / public system, circuit commonization in the apparatus is achieved. This can be achieved, and the apparatus can be simplified.

In the dedicated / public systems of the fifth and sixth embodiments, like the third embodiment, when determining the connection or switching of the communication terminal, not only the reception level of the first search code but also the required transmission power considering the radio wave loss and the amount of interference are determined. In the same manner as in the fourth embodiment, the communication terminal device requests a desired communication service for a system requested for connection, and reports information such as reception level information measured by itself or congestion of other systems, and the base station communicates. It is also possible to introduce the connection target system by judging its own system status based on the information from the terminal device.

In the first to sixth embodiments, a case in which the first search code FSC and the second search code SSC are multiplexed to the control channel signal in the masking part of the control channel signal is described. It is also applicable to the case where the search code FSC and the second search code SSC are separated in time and multiplexed to the control channel signal.

In the first to sixth embodiments, a case in which the short code SC0 multiplied in advance and the long code LCj is multiplied to the control channel signal is described. However, the present invention does not multiply the long code LCj to the control channel signal in advance. The case is also applicable.

In Examples 1 to 6, a different value may be used for each system as a threshold value. In this case, the threshold may be set or stored in advance for each system, and may be calculated by the communication terminal device based on the information from the base station of each system or based on the information from the base station.

In addition, since the minimum reception level for connecting to the system and the reception level for detecting a handover target during connection are usually different from each other, a plurality of thresholds may be used for each reception level and for each processing. Accordingly, appropriate threshold values can be determined according to the respective processing levels according to the respective reception levels, thereby enabling optimal connection processing. In addition, when the threshold value or more is exceeded, the processing can be simplified by not measuring the reception level of another system. Also in this case, the threshold may be set or stored in advance for each system, and may be notified from the base station of each system or calculated by the communication terminal device based on the information from the base station.

As described above, since the radio communication apparatus and the radio communication method of the present invention use signals having a common mask symbol structure, the connection target can be detected or switched automatically. As a result, it is possible to use a small system (cell radius: low transmit power is possible) or an empty system. In addition, since the communication terminal apparatus can be efficiently accommodated both locally and in frequency, the use efficiency of the frequency can be improved. In addition, the power consumption of the communication terminal device can be reduced, and the life of the communication terminal device can be extended.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

This application is based on Japanese Patent Application No. 10-348283 filed on December 8, 1998, which is incorporated by reference in its entirety.

Claims (12)

A receiving unit for receiving a signal having a configuration having at least one first search code in a unit frame from a communication counterpart of at least two different systems, A selection unit for comparing the quality of the signal of the configuration received from the communication partners of the at least two different systems and selecting a communication partner to be connected based on the comparison result; Connection unit performing connection processing for the selected communication party Communication terminal device comprising a. A receiving unit which receives a signal having a configuration having at least one first search code in a unit frame from a specific communication partner, A judging unit for performing threshold value determination on the quality of the signal of the configuration received from the specific communication counterpart; A connection unit that performs a connection process for the specific communication counterpart only when the quality exceeds a predetermined threshold value. Communication terminal device comprising a. The method of claim 1, A synchronization processor for performing synchronization processing using the second search code, And a decoding unit for decoding the information about the transmission from the communication partner by using the notification channel signal. The quality includes information about the decoded transmission. Communication terminal device. The method of claim 1, A measuring unit measuring a reception quality of a communication counterpart of the at least two different systems; A notification unit for notifying the specific communication party of the information of the reception quality; More, The connection unit performs connection processing on the connection target according to the connection target information selected by the specific communication partner based on the notified reception quality. Communication terminal device. A frame constitution unit constituting a frame having at least one first search code in a unit frame, Transmitter for transmitting the signal having the above configuration Base station device comprising a. The method of claim 5, A determination unit which determines whether the communication partner can be accommodated in the own system based on the reception quality information measured by the communication partner; A detection unit for detecting another acceptable system when the communication partner cannot be accommodated; A notification unit for notifying the communication partner of the detection result Base station device comprising a. Receiving a signal having a configuration having at least one first search code in a unit frame from a communication counterpart of at least two different systems, Comparing the quality of the signal of the configuration received from the communication partners of the at least two different systems and selecting a communication partner to be connected based on the comparison result; Process of performing connection process on selected communication counterpart Wireless communication method comprising a. Receiving a signal having a configuration having at least one first search code in a unit frame from a specific communication partner, Performing a threshold value determination on the quality of the signal of the configuration received from the specific communication counterpart; Performing a connection process for the specific communication counterpart only if the quality exceeds a predetermined threshold value. Wireless communication method comprising a. The method of claim 7, wherein Performing a synchronous process by using the second search code; Decoding the information on the transmission from the communication partner by using the notification channel signal; The quality includes information about the decoded transmission. Wireless communication method. The method of claim 7, wherein Measuring a reception quality of a communication counterpart of the at least two different systems; Notifying the reception information of the specific communication party; More, Performing connection processing on the connection target according to the connection target information selected by the specific communication counter based on the received reception quality notified. Wireless communication method. Constructing a frame having at least one first search code in a unit frame, Transmitting a signal having the above configuration Wireless communication method comprising a. The method of claim 11, Determining whether the communication partner can be accommodated in the own system based on the reception quality information measured by the communication counterpart; Detecting other acceptable systems when the communication partner cannot be accommodated; Informing the communication counterpart of this detection result Wireless communication method further comprising.